JPH0417548A - Motor actuator - Google Patents

Abstract

PURPOSE:To enlarge stroke with small size by transmitting the rotation of a motor to a pinion through a speed reduction mechanism, and converting it into a rectilinear motion with the rack engaging with this pinion. CONSTITUTION:A motor actuator 1 comprises a motor 2, a speed reduction mechanism 3, which transmits the rotational output of the motor 2 after reducing the speed, a pinion 4, which constitutes one part of this speed reduction mechanism 3, a reciprocating member 6, which is equipped with a rack 5 engaging with this pinion 4 and works on the object to be driven, and a case 7, which houses these. And it is so constituted that the reciprocating member 6 works on the object to be driven, being reciprocated rectilinearly by the rotation of the motor 2. This way, it is made possible to convert the rotational motion into a rectilinear motion by a rack and a pinion and protrude or pull in the reciprocating member by a specified amount, so the size of the actuator can be miniaturized, and the operating speed and the thrust of the reciprocating motion can be set constant freely and simply.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a motor actuator. More specifically, the present invention relates to a motor actuator that converts the rotation of a motor into linear reciprocating motion and outputs the linear reciprocating motion.

(Prior art) As an actuator that gives reciprocating displacement to a driven body,
Conventional electrically controlled actuators use plunger magnets (electromagnetic solenoids) to move the Rondo in a straight line, actuators that convert the rotary movement of a motor into linear movement using pulleys and wires, or crank 8! 2. Description of the Related Art Actuators and the like that convert the rotational motion of a motor into linear motion using a horizontal axis are widely known.

(Problem U to be solved by the invention) However, since actuators using plunger magnets use magnetic attraction force, they cannot have a large stroke, and the operating force fluctuates greatly within the stroke. Furthermore, since it operates instantaneously, the operation noise is loud, and there is also the problem that electricity must be continuously supplied to maintain the moving state.

Further, in the case of an actuator using a pulley and a wire, the actuator can only operate in the winding direction, and if the diameter of the pulley cannot be made very large, there is a problem in that the amount of wire winding is restricted and the stroke cannot be taken.

Furthermore, in the case of an actuator that uses a crank mechanism,
If the rod is not long enough, true linear motion will not occur, resulting in a larger configuration.Moreover, in the case of this crank-type actuator, a longer rod will reduce transmission efficiency and degrade responsiveness. It has problems.

An object of the present invention is to provide a small motor actuator that performs reciprocating motion at a constant speed and can have a large stroke.

(Means for Solving the Problems) In order to achieve the above object, the motor actuator of the present invention includes a motor, a reduction mechanism that is connected to the motor and transmits its rotational output while decelerating it, and a motor actuator that includes a motor, a reduction mechanism that is connected to the motor and transmits its rotational output while decelerating it, and A pinion that is continuously provided in the reduction mechanism,
It comprises a reciprocating member having a rack that meshes with the pinion and acting on the driven body, and the reciprocating member is configured to be capable of reciprocally moving in a straight line by rotation of the motor.

Further, in the motor actuator of the present invention, a slip mechanism is provided in a rotation transmission path between the motor and the reduction mechanism, which slips due to overload and interrupts rotation transmission.

Further, in the motor actuator of the present invention, an operation position detection means is provided in the reciprocating member or the reduction mechanism, and the motor is rotated forward, stopped, or reversed in accordance with an output signal from the operation position detection means. ing.

(Function) Therefore, the rotation of the motor is decelerated t! It is transmitted to the final stage pinion via the A ellipse, and converted into a linear motion in the rack that meshes with the pinion, causing the reciprocating member to protrude or retract by a predetermined amount.

Further, when a slip mechanism is provided in a rotation transmission path including a deceleration mechanism, when braking or reverse rotation is applied from the reciprocating member side, the transmission of force from the reciprocating member side is sometimes interrupted.

(Example) Hereinafter, the configuration of the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 shows an embodiment of the motor actuator of the present invention. This motor actuator 1 consists of a motor 2, a reduction gear 3 that decelerates and transmits the rotational output of the motor 2, and a part of this reduction mechanism 3. or deceleration I! A reciprocating member 6 comprising a pinion 4 provided separately from the treetop 3 and a rack 5 meshing with the pinion 4 and acting on a driven body.
and a gauge 7 that accommodates them, and is provided so that the rotation of the motor 2 causes the reciprocating member 6 to linearly reciprocate and act on the driven body.

A worm 8 is attached to the output shaft of the motor 2 serving as a drive source, and rotation is transmitted to the rack 5 of the rod 6 via the worm 8 and a reduction gear a 3 including a worm wheel 9 that meshes with the worm 8. It is configured. The speed reduction mechanism 3 includes a worm 8, a worm wheel 9, a pinion 10 coaxial with the worm wheel 9, a gear 11 meshing with the pinion 10, and a pinion 4 coaxial with the gear 11. .

A reciprocating member, such as a rod 6, that provides displacement to a driven body has a rack 5 formed on its base end side, and is engaged with a pinion 4 of the speed reduction mechanism 3. A conductive slide spring 12 is provided on the surface of the rod 6 opposite to the portion where the rack 5 is formed.
are fixed, and electrical contacts 13a, 13b, 13c
It is provided so that it can reciprocate within the gauge 7 provided with. This rod 6 is held by a bottle or roller 14 buried on the exit side of the gauge 7, and is provided so as to be able to smoothly move linearly in a fixed direction. Further, the rod 6 is provided with a stopper 15 that engages with the gauge 7, and when the stopper 15 comes into contact with the case 7, one stroke end of the rod 6 is determined.

The slide spring 12 has three fixed electrical contacts 13a installed at equal intervals on the case 7.

One of the contacts 13b and 13c, for example 13a, is used as a common contact and forms a closed circuit with one of the remaining contacts 13b and 13c. For example, as shown in FIG. 5, the central electrical contact 13a and the right electrical contact 13c or the center electrical contact 13a and the left electrical contact 13b. The signal obtained by closing the electrical contacts provides the drive circuit 25 external to the actuator with information on the position of the rod 6, ie whether the rod 6 is protruding or in its original position. A position detection means 20 is constituted by the above-mentioned slide spring 12 and electric contacts 13a, 13b13c.

Note that the worm wheel and pinion 10 are integrally formed coaxially. Further, the gear 11 and the pinion 4 are arranged coaxially, and a slip mechanism 16 is configured between them. The slip mechanism 16 includes a pinion 4 that is fixed to the driven shaft 17, a gear 11 that is rotatable relative to the driven shaft 17, a friction plate 18 that rotates together with the driven shaft 17, and a friction plate 18 that presses the gear 11 against the driven shaft 17. It is composed of a disc spring 19 for rotation. Incidentally, the disc spring 19 is press-fitted and fixed to the driven shaft 17. Therefore, when a load (torque) less than a set value acts between the gear 11 and the pinion 4, the rotation of the gear 11 is transmitted to the driven shaft 17 via the friction plate 18, and then to the pinion 4.
However, when an overload exceeding a set value is applied, slippage occurs between the gear 11, the friction plate 18, and the disc spring 19, causing the gear to idle. Note that a DC motor is used as the motor 2.

The motor actuator of the present invention configured as described above operates as follows.

Normal operation Normally, the rod 6 is in its original position [the state shown in FIG. 1(A)]. Therefore, when the motor 2 is energized, the rotation of the motor 2 is transmitted via the reduction mechanism 3 to the pinion 4 that meshes with the rack 5 of the rod 6, causing the rack 5 to move in a straight line and moving the rod 6 in its original position to the case. Let it stick out from 7. When the motor 2 is pushed out by a predetermined amount [the state shown in FIG. 1(B)], this is detected by the position detection means 20, which will be described later, and the external circuit 25 cuts off the power to the motor 2. Further, the rod 6 is not pushed out any further because the stopper 1°5 comes into contact with the case 7.

Eaves! The slide spring 12 fixed to the benefit rod 6 is
The position of the rod 6 is detected by connecting two of the fixed contacts 13a, 13b, and 13c at the location to form a closed circuit. That is, in FIG. 1, if the original position is
), the fixed contact 13a is used in common, and the fixed contact 13. A closed circuit is formed with c, and the protruding position [
In the position shown in FIG. 1(B), the common fixed contact 13a and the fixed contact 13b form a closed circuit.

” i see! When a sudden force is applied from the rod 6 side, the slip mechanism 16 built into the gears in the deceleration mechanism 3 slips, cutting off the transmission of rotational force and causing the gears in the actuator 1 to slip. For example, when the rod 6 is in operation or in the protruding position, if a force to push the rod 6 is applied from the outside, the slip f1!1i16 will slip and the push from the rod 6 will be prevented. The force in the direction (the force that tries to rotate motor 2 in the opposite direction) is
This prevents damage to the gears of the actuator and the entire actuator. Further, by utilizing this slip state and comparing the time from the origin signal for position detection to the protrusion position signal and the expected operating time, it is possible to detect an abnormality.

FIG. 4 shows an example in which the motor actuator of the present invention is incorporated into a magnetic attraction type opening/closing door mechanism, for example, for opening the door of an electric refrigerator. A door 21 of the refrigerator is attached to a refrigerator body 22 via a hinge so as to be openable and closable. A backing 23 made of a magnet is attached to the door 21 of this refrigerator.
is built in, and when the door is closed, the refrigerator body 22
and are attracted by magnetic force. In a refrigerator, the adsorption force between the door 21 and the refrigerator main body 22 determines the state of isolation from the outside air, so a large adsorption force is required.

Therefore, the opening operation requires a correspondingly large amount of force, which is a burden on people with weak strength such as children, the elderly, and people with physical disabilities. Therefore, the motor actuator 1 shown in Fig. 1 is installed on the refrigerator main body 2211111 or the door 21 side, and the motor actuator 1 is operated by operating the switch 24 to automatically open the door at least until the suction force is released. I have to.

I lost my belly! When the refrigerator door 21 is closed, the rod 6 of the motor actuator 1 is at the origin and in the state shown in FIG. 1 (A)]
It is in. Therefore, when the switch 24 provided on the surface of the door 21 is turned on, the motor 2 is energized by the action of the external drive circuit 25, and the rod 6 is protruded and the door 21 is turned on.
Push them apart to release the attraction force caused by the magnetic force. Even a child can easily open the door 21 from this position. Furthermore,
After stopping the time until the door 21 is manually opened by a timer 26 in the drive circuit 25, the motor 2 is restarted.
Apply a reverse voltage to move rod 6 to the origin [Fig. 1 (A) state]
and complete one cycle of operation.

1. When the user attempts to close the door 21 while the 11-lumen rod 6 is being ejected or stopped at the ejecting position,
The slip 8111116 slips, cutting off transmission of rotational force from the motor 2, and pushing the rod 6. This prevents damage to gears and the like within the actuator 1.

Also, when the rod 6 is being pushed out, if there are children or other items within the movement range of the door 21,
The slip II crown 16 is activated, the transmission of rotational force is cut off, the door 21 is no longer opened, and the actuator 1 itself is safe without being damaged.

Although the above-described embodiment is an example of a preferred embodiment of the present invention, it is not limited thereto, and various modifications can be made without departing from the gist of the present invention.For example, in this embodiment, the drive source Although a DC motor is used in A gear train consisting only of gears may be used, and the number of deceleration stages is not limited. Also, the position detection means 20 is not limited to the combination of the slide spring 12 and the fixed contacts 13a, 13b, 13c of this embodiment, but may be a combination of, for example, a magnet or the like. It may be a combination of reed switches or Hall ICs, etc. Also, the detection position is not limited to two points, for example, if the motor 2 is a pulse motor, only the origin may be detected and stopped at the number of input pulses,
Conversely, continuous changes may be detected like a potentiometer. Further, the position detection means 20 is not limited to being incorporated into the rod 6, but may be incorporated into the reduction gear 3, or may be provided separately as a structure independent from these. Furthermore, the slip mechanism 16 is not limited to the one in this embodiment, and may be any mechanism that slips between the worm wheel 9 and the pinion 10, or between the motor 2 and the worm 8, or any other part of the rotation transmission path. .

(Effects of the Invention) As is clear from the above explanation, since the motor actuator of the present invention converts rotational motion into linear motion using the rack and binion, it is possible to simply lengthen the reciprocating member without changing the size of the actuator. Can be made smaller. Furthermore, the operating speed and thrust of the reciprocating motion can be freely and easily set to a constant value.

Furthermore, if a slip mechanism is built-in, the thrust is limited when a load exceeding a set value is applied, making it safe. Also,
Since it has a built-in position detection mechanism, the original position can be reliably reproduced. Furthermore, when multiple detection positions are set, the magnitude of the load can be determined by comparing with the expected operating time.
It is also possible to detect abnormal operations, abnormal loads, etc.

(Field of Utilization of the Invention) The motor actuator of the present invention can be used as a drive source in various fields without any particular application, but it is particularly suitable for magnetic adsorption type door opening/closing devices, such as the above-mentioned refrigerator door opening/closing bag! In addition, it can be applied to door opening devices for system kitchens, lock opening/closing mechanisms for safes, etc. Furthermore, the motor actuator of the present invention can be applied to a product ejection mechanism of a vending machine, an automatic transmission of an automobile, etc., a drive device of a drain valve for an electric washing machine, and the like.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing an embodiment of the motor actuator of the present invention, in which (A) shows the original position and (B) shows the extended state. FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1. FIG. 3 is an enlarged view showing the slip mechanism. FIG. 4 is a perspective view showing an embodiment in which the motor actuator of the present invention is incorporated for opening and closing the door of a refrigerator. FIG. 5 is a block diagram of an actuator drive circuit. 1... Motor actuator, 2... Motor, 3...
...Reduction mechanism, 4... Binion, 5... Rack, 6
... Reciprocating member (rod), 7... Gauge, 12
...Slide spring, 13A, 13B, 13C...Fixed electrical contact, 16...
- Slip mechanism, 21... Refrigerator door, 22... Refrigerator body, 24... Switch.

Claims (3)

[Claims] (1) A motor, a speed reduction mechanism that is connected to the motor and transmits its rotational output while decelerating it, a pinion that is installed in or continuous with the speed reduction mechanism, and a rack that meshes with the pinion. 1. A motor actuator comprising a reciprocating member that acts on a driven body, the reciprocating member being capable of being driven in a reciprocating straight line by rotation of the motor. (2) The motor actuator according to claim 1, further comprising a slip mechanism provided in a rotation transmission path between the motor and the speed reduction mechanism, which slips and interrupts rotation transmission due to overload. (3) The motor according to claim 1 or 2, wherein an operating position detecting means is provided in the reciprocating member or the speed reduction mechanism, and the motor is rotated forward, stopped, or reversed in accordance with an output signal from the operating position detecting means. actuator.